diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 420d24f..78648f8 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -336,13 +336,9 @@
 static void dock_remove_acpi_device(acpi_handle handle)
 {
 	struct acpi_device *device;
-	int ret;
 
-	if (!acpi_bus_get_device(handle, &device)) {
-		ret = acpi_bus_trim(device);
-		if (ret)
-			pr_debug("error removing bus, %x\n", -ret);
-	}
+	if (!acpi_bus_get_device(handle, &device))
+		acpi_bus_trim(device);
 }
 
 /**
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index b206ce5..774b17d 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -52,6 +52,7 @@
 
 static LIST_HEAD(acpi_device_list);
 static LIST_HEAD(acpi_bus_id_list);
+static DEFINE_MUTEX(acpi_scan_lock);
 DEFINE_MUTEX(acpi_device_lock);
 LIST_HEAD(acpi_wakeup_device_list);
 
@@ -127,13 +128,8 @@
 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 		"Hot-removing device %s...\n", dev_name(&device->dev)));
 
-	if (acpi_bus_trim(device)) {
-		printk(KERN_ERR PREFIX
-				"Removing device failed\n");
-		goto err_out;
-	}
-
-	/* device has been freed */
+	acpi_bus_trim(device);
+	/* Device node has been released. */
 	device = NULL;
 
 	/* power off device */
@@ -1616,19 +1612,22 @@
 int acpi_bus_scan(acpi_handle handle)
 {
 	void *device = NULL;
+	int error = 0;
+
+	mutex_lock(&acpi_scan_lock);
 
 	if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 				    acpi_bus_check_add, NULL, NULL, &device);
 
 	if (!device)
-		return -ENODEV;
-
-	if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL)))
+		error = -ENODEV;
+	else if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL)))
 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 				    acpi_bus_device_attach, NULL, NULL, NULL);
 
-	return 0;
+	mutex_unlock(&acpi_scan_lock);
+	return error;
 }
 EXPORT_SYMBOL(acpi_bus_scan);
 
@@ -1655,8 +1654,10 @@
 	return AE_OK;
 }
 
-int acpi_bus_trim(struct acpi_device *start)
+void acpi_bus_trim(struct acpi_device *start)
 {
+	mutex_lock(&acpi_scan_lock);
+
 	/*
 	 * Execute acpi_bus_device_detach() as a post-order callback to detach
 	 * all ACPI drivers from the device nodes being removed.
@@ -1671,7 +1672,8 @@
 	acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
 			    acpi_bus_remove, NULL, NULL);
 	acpi_bus_remove(start->handle, 0, NULL, NULL);
-	return 0;
+
+	mutex_unlock(&acpi_scan_lock);
 }
 EXPORT_SYMBOL_GPL(acpi_bus_trim);
 
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 9e2b1f6..d1a6f4a 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -742,8 +742,7 @@
 		/* this shouldn't be in here, so remove
 		 * the bus then re-add it...
 		 */
-		ret_val = acpi_bus_trim(device);
-		dbg("acpi_bus_trim return %x\n", ret_val);
+		acpi_bus_trim(device);
 	}
 
 	ret_val = acpi_bus_scan(func->handle);
@@ -772,11 +771,8 @@
 		return retval;
 	}
 
-	retval = acpi_bus_trim(device);
-	if (retval)
-		err("cannot remove from acpi list\n");
-
-	return retval;
+	acpi_bus_trim(device);
+	return 0;
 }
 
 static void acpiphp_set_acpi_region(struct acpiphp_slot *slot)
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index fc76b1f..ad0a86a 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -386,7 +386,7 @@
 void acpi_bus_unregister_driver(struct acpi_driver *driver);
 int acpi_bus_scan(acpi_handle handle);
 void acpi_bus_hot_remove_device(void *context);
-int acpi_bus_trim(struct acpi_device *start);
+void acpi_bus_trim(struct acpi_device *start);
 acpi_status acpi_bus_get_ejd(acpi_handle handle, acpi_handle * ejd);
 int acpi_match_device_ids(struct acpi_device *device,
 			  const struct acpi_device_id *ids);